Mercruiser 120hp to SB Chevy Swap?

[Rockyncali]

I have the 120hp and it's worked great using it for a multi purpose boat wakeboarding/fishing/cruising but now that my boat is used solely for wakeboarding (bought little fishing boat) I have it weighted down to create enough wake to make it fun. Of course now it seams to dog on the hole shot. I was wondering if I did the swap to a small block chevy is there any parts that can be used from the 4 cyl. The less money I spend the better. I have the engine/computer/harness all that stuff. I know I'm going to need a new water pump, exhaust. Also that reminds me where can I get that stuff cheap. Any help is good help. Thanks.

 

[WillyBWright]

Re: Mercruiser 120hp to SB Chevy Swap?

First you'd better be sure the boat is capable of mounting a V8. The inlines have a single motor mount in the front. Vs mount on stringers on the side. Many boats are built for one or the other. Many are built for both. Have you considered changing to a smaller pitched prop? $150 is sure a whole lot cheaper than the thousands you'd spend converting. Very few of the 120 parts would do you any good on the smallblock. Alternator, bell housing(?), that'd be about all.

 

[Rockyncali]

Re: Mercruiser 120hp to SB Chevy Swap?

I thought about the prop change idea but right now it already tops out at about 27 with all the weight in it. As far as the change goes. The mounts are the thing that I'm worried about most. I have the outdrive and engine from my old boat that was stolen and ran on the rocks. I didn't keep the fly wheel but I kept the exhaust manifolds and an assortment of other things. I know it will fit but not sure about building motor mounts.